Die-head for cutting taper and straight threads



A. F. BREIYTENSTEIN. DTE HEAD FDH CUTTING TAPER AND STHATGHT THREADS.lAPPLICATION FILED JULY 2,1920.

1,396,989. Patented N0v.'15, 1921.

2 SHEETS-SHEET l.

f 1 "*wllllil IIIIIMIIIII* 1 if "HI Y Hllllillll A. F. BRETTENSTEIN. DIEHEAD FDH CUTTING TAPER AND STRAIGHT THREADS.

APPLICATION FILED JULY 2,1920.

Patented NDV'. 15, 1921.

2 SHEETS-SHEET 2.

ALBERT n. BREITENSTEIN, 0r NEWA HAVEN, CONNECTICUT, AssrGNoR To THEGEOMETRC T001, en or New HAVEN, CONNECTICUT, A CORPORATION.

DIE-HEAD FOB CUTTING TAPER AND STRAIGHT THREADS.

S ecicaton of Letters Patent.

Patented Nev. i5, i921.

Application filed July 2, 1920. Serial No. 393,587.

To all 'wlw/m` t may concern.:

Be it known that ALBERT F. BnnirnN- s'rniN, a citizen of the UnitedStates, residing at New Haven, in the county of New Haven and State etConnecticut, have invented a new and useful lmprovement in Die-Heads forCutting Taper and Straight Threads; and l do hereby declare thefollowing, when taken in connection with the accompanying drawings andthe characters of reference marked thereon, 'to be a full, clear, andexact description of the same, and which said drawings constitute partof this application and represent, iii- Figure 1, a perspective view ofa diehead embodying my invention.

F ig. 2, a view thereof in vertical central section.

Fig. 3, a reverse plan view thereof, the split outer end of the arm ofthe carrierplate being shown in section.

Fig. 4;, a plan view thereof.

Fig. 5, a view thereof in transverse section on the line 5 5 of Fig. 2,with the carrierplate removed.

Fig. 6, a view thereof in transverse section on the line 6-6 oi' Fig. 2.

F ig. 7, a detached perspective View ot the segment with its extensionand cleat.

Fig. 8, a detached view of the interchange able taper-thread unit.

Fig. 9, a view partly in elevation and partly in section of theinterchangeable straight-thread unit. i

Fig. 10, a'view of a taper-thread stay-bolt, as produced with myimproved die-head.

My invention relates to an improvement'in die-heads 'for cutting taperor straight threads as may be desired, being` primarily designed forthreading taper-thread or straight-thread stay-bolts, but not limited tosuch use. The object of my invention is to produce at. a low cost formanufacture, a simple and etcient die-head constructed with particularreference to conversion Jfor cutting straight or tapered threads withoutthe expenditure of the time called for byl claims.

In carrying out' my invention, as herein shown, l construct a die-head,the general features of which are of standard type and consist of askeleton body 7, the lower face of which is formed with four radialslots 8 .tor the reception of as ymany chasers 9 having their upperfaces transversely slotted, as usual, as at 10, for the yreception oftangentially arranged cam-lugs 11 formed upon thelow'er face of anoscillating cam-ring 12 which 1s mounted upon the body 7 and held inplace thereupon by a circular carrierplate 13 secured in place by threedowels le and three screws 15. lt is to be understood, however, that thenumber of chasers may be varied as desired. rlhe upper face of the plate13 is formed with a large, concentric recess 16 by meansof which thedie-hcad is secured to the non-rotatable spindle or" a stay-bolt machinein the usual manner, the die-head remaining stationary while the work ismounted in andfrotated with any suitable chuck.

The upper edge of the cam-ring 12 is formed with a deep annular recess17 which receives a helical spring 18 which throws the cam in thedirection of opening the chasers. This spring abuts at one end upon astud 19 (Fig. 5) depending from the plate 13,

- and at its opposite end against a segmentretaining cleat 2O located inthe recess 17 and secured by a screw 21 to the cam-ring 12.

The recess 17 in the upper face of the cam-ring 12 also receives anoscillating segment 22 having a wedge-shaped extension 23 secured to itby screws 24, this extension projecting laterally outward beyond theperiphery oi the die-head through a slot 25 in the upper edge of thecam-ring, as shown in Figjl. The said segment 22 carries a dependingcoupling-stud 26, the lower end of which is interposed between the innerends of two adjusting-screws 27 tangentially mounted in the cam-ring, asshown in Fig. 6, the said cam-ring being formed with a slot 28 for thedownward projection into it 'ot the said stud 26. The stud 26 couplesthe cam-ring 12 and the segment 22, while the adjusting-screws 27provide for adjust- .Y 8 illustrating a ing their relative relations sothat the ring may be adjusted in position with reference to the chasersso as to operate the same in accordance with the desired diameter of thethread to be cut. The segment 22 is prevented from tilting by theprovision of the cleat 20 with a tongue 29 which overhangs acorresponding tongue 30 upon the acent end of the segment.

As in standard automatic die-heads of the type being described, thechasers 12 are' automatically retired after the completion of thecutting operation by means of the spring 18. The work having beenremoved, the chasers are again closed preparatory to another threadingoperation by means of a closing roller 31 journaled upon a stud 32secured in the cam-ring by a pin 33, as

shown in Fig. 6, this roller being acted upon at a predetermined time byan abutment in the stay-bolt machine. The throw of the cam-ring in thedirection of opening is limited by a stop-screw 34 mounted in the ringand projecting into a slot 35 formed in the body 7 and receiving at oneend a hardened stop-pin 36 against which the inner end of the screw 34engages to limit the opening movement of the cam-ring.

As shown, the cam-ring 12 is formed with a long, concentricclearance-slot 37 leading into a radial tool-hole 38 formed in the body7 and permitting a cutting-tool to be inserted into the bore 39 of thedie-head so as to enable a stay-bolt to be turned down, as at 40,between its threaded portions 41 and 42, if desired, or to permit thework, whatever its character, to be turned down between its threadedends.

I have thus far described my die-head as a self-contained, separatelyorganized structure, in its main fcatures,`of standard type, thisconstituting the die-head unit of my improvement, but characterized asto novelty by its projecting segment-extension (Fig.

which is a new feature of automatic diehead construction. I will nov7proceed to describe two interchangeable thread-controlling units, suchas'are designed to be used with a die-head of the type described. Fig.taper-thread unit and Fig. 9, a straight-thread unit.

For the interchangeable reception of these thread-controlling units forthe conversion of the die-head for cutting taper or straight threads,as'desired, the carrier-plate 13 is formed with a radial arm 43 providedwith a vertical threaded opening 44. the outer Y wail of which isintersected by slot 45 split ting the outer end of the arm intoclampinglugs 46 drawn together by a locking-screw 47. The arm 43 is thusadapted to mount either one for the other of the threading units. as maybe desired, without disassembling either of the units or disassemblingthe die-head proper.

The taper-thread unit (Fig. 8) consists of a tubular body 48 provided atits lower end with screw-threads 49 adapting it to` be screwed into thethreaded hole 44 in the arm 43 in which it is clamped by the screw 47,the body having an integral heXagon 50 for the application of a wrenchby means of which the unit is screwed into and out of the arm 43. Thetubular body 48 receives a plunger 51, the projecting lower end of whichconsists of a tapered head or cone 52 which coacts with the inclinedforward edge of the wedge-shaped segment-extension 23, as shown inFig. 1. The stem of the plunger 51 is surrounded by a helical spring 53located within the tubular body 48 and eX- erting constant effort toforce the plunger downward. At its upper end, the plunger is formed witha transverse slot 54 for the reception of a vertically adjustabletrippingfinger 55 which co-acts with an abutment 56 (Fig. l) indicatedby broken lines and forming a feature of the stay-bolt machine. For thereception of the finger 55, the upper end of the tubular body is formedwith a guide slot 57. The extreme upper end of the plunger is internallythreaded for the reception of a set-screw 58 which impinges upon theupper edge of the iinger 55 and holdsV the same rigidly in the slot 54of the plunger. To provide for varying the length of the thread to becut, the upper portion of the body is threaded, as at 59, for thereception of an adjusting-nut 60Y and a lock-nut 61, these being locateddirectly below the tripping-finger which bears upon them and which israised or lowered as required by them.

As shown in Fig. 2 of the drawings, these nuts 60 and 61 are positionedso as to provide for the co-action of the full length of the taperedhead 52 of the plunger with the segment extension '23. 1f it is desired,however, to shorten the length of the thread to be cut, the nuts areraised upon the threaded portion 59 of the tubular body 48, whereby thetripping-finger is lifted with the effect of lifting the tapered head 52of the plunger 51 with respect to the segmentextension V23. Thetaper-thread unit thus described, is self-contained and ismounted in thearm 43 of the die-head for converting the same for cutting taperthreads, without disassembling the die-head.

For cutting straight threads, I employ a i,

separate straight-thread unit consisting of a tubular body 62 having itslower end threaded as at 63 for insertion into the threaded hole 44 ofthe arm 43 of the carrier-plate 13. The tubular body 62 receives aplunger 64 having its lower end cut Vtransversely and slightlyflattened, as at 65 for co-action with the forward edge of thesegmental-extension 23. The said body 63 is furnished with integralwrench-faces 66 whereby the unit is screwed into and unscrewed from thearm 43. The plunger 64 is operated by a helical spring 67 located withinthe body and exerting a constant ettortrto force the plunger downward,the same as in the construction previously described At its upperend,the plunger is transversely slotted for the reception of atrippingfinger 68 secured in place by a set-screw 69 and passingtransversely through a slot formed in the upper end of the body 62. Noprovision is made in this unit for adjusting theA tripping-linger 68,but provision is made in the stay-bolt machine for adjusting theposition of the abutment 56 as may be required. The straightthreadcontrolling unit of Fig. 9 converts the die-head for straight-threadcutting without disassembling the same. v

lt will thus be seen that by constructing the die-head andthread-controlling units as separate organizations, I am able to convertthe die-head for taper-thread cutting or straight-thread cutting andvice versa without disassembling the `die-head or in any way changingit. It will also be apparent that the operation of interchanging thethread-controlling units is easily effected.

Let it be assumed that the die-head is mounted upon the non-rotatablespindle of a standard stay-bolt machine and converted for taper-threadcutting by the mounting in it of the taper-thread controlling unit. Now,as the die-head descends with the spindle, the tripping-finger 55 of theunit engages at the beginning of the threading operation, with the upperface of the abutment 56 of the machine V rlfhis arrests the downwardmovement of the finger 55 and consequently begins the lifting of theplun ger 51 and its cone 52 with respect to the inclined forward edge ofthe wedge-shaped segmentextension 23 which is held against it by thecam-spring 18. Therefore, as the cone 52 is lifted, it will ride overthe edge of the extension, which will thus be allowed to turn under theinfluence of the spring, at a rate corresponding` to the lifting of thecone. As the extension 23 turns, so does the segment 22 and hence thecam-ring 12 and the chasers 9. rlhis low progressive turning of thecam-ring in the direction of open ing, continues throughout thethreading operation until finally when the cone 52 is liftedsufliciently for its lower end to clear Athe segment-extension 23, thecam-spring 18 operates to complete the opening movement of the cam-ring,whereby the chasers are thrown into their fully open positions, in whichthey automatically release the work being threaded. The die-head is nowlifted into its starting position, at whichtime the closing roller 31coeacts with its appropriate abutment upon the stay-bolt machine toforce the cam-ring against the tension of its spring 18 into its fullyclosed position, at

whichitime the segment 23 is carried so far beyond the cone 52 of theplunger 51 as to permit the spring 53 thereof to force it downward intoits starting position, as shown by Fig. 1. .The operation abovedescribed ing the position of the tripping-finger 55 upon the tubularbody t8 of the taper-thread controlling unit, the length of the threadcut may be varied as desired.

'io convert the die-head for cutting straight threads, the taper-threadcontrollingI unit of Fig. 8 is removed and replaced `by thestraight-thread controlling unit of Fig. 9, ln using this unit, theabutment 56 is adjusted to coact with the tripping-finger 68 at themoment it is desired to release the cam-ring for automatically openingthe chasers, the tripping-finger simply descending through space untilit is brought into engagement with the abutment. During the descent ofthe die-head with the spindle of the machine, the flattened, projecting,lower er 65 of the plunger 64 remains in engage ment with the forwardedge of the extension rlhen when the linger 68 engages with the abutment56, thc segment-extension 28 is released and the cam-ring allowed tomove at once from its full closed to its full open position instead ofgradually, as in the construction previously described.

i-is shown in:y Fig. 1, graduations 71 are placed. upon the externalfaces of the body, 7 and cam-ring` 12 to guide the user in turning` vheadjusting-screws 27 as required for adjusting* the projection 28 withreference to the cam-ring.

l claim: i

1. l'n a die-head, the combination with a self-opening die-head unit, ofan independently organized, thread-controlling unit adapted to beinserted into and removed from` the diehead unit without disassem blingthe same, and having a yielding plunger retiring during the progress ofthe work antl returning to its initial position after the completion ofthe work.

2. ln a convertible die-head, the combination with a die-head unit, ofan independently organized, thread-controlling unit for insertion intoand removal from the die-head unit without disassembling the same, thesaid unit having a spring-actuated plunger formed with a tapering headco-acting with an abutment external to the die-head.

3. A die-head unit having a body, chasers mounted therein, a cam-ringfor operating the chasers, projection connected with thek `cam-ring andprojecting from the die-head,

and a removable thread-controlling unit 4, asv-agee@ mounted upon thedie-head in position to coa't with the said projection and having atripping-finger co-acting with an external Iabutment.

A die-head having a body, chasers mounted therein, a cam-ring'foroperating the chasers, a projection Vadjustably connected with thecam-ring, a plate secured to the said body, and an independentlyorganized, removable, thread controlling unit adapted to be mounted inthe plate in position to co-act with the said projection and to beoperated by an external abutment.

A die-head having a body, chasers mounted therein, a cam-ring foroperating the chasers, a segment attached to the camand provided with alateral projection,

adjustable connection between the said segment and ring, a plate securedto the body, and an independently organized, removable,thread-controlling unit mounted in the said plate and having a plungerformed with a conical end for co-action with the said projection, and atripping-inger for co-action with an external abutment.

6; In a die-head, the combination with a body, of chasers mountedtherein, a springactuated cam-ring for operating the chasers, a segmentmounted in the said ring, a wedge- 'shaped projection carried by thesegment and projecting fromthe periphery of the die-head, means foradjustably connecting the segment and cam-ring, a carrier-plate securedto the said body, and a self-contained thread-controlling unit adaptedto be removably mounted in the said plate and having a plunger forco-acting with the said proj ection, and adapted to be moved by meansindependent of the die-head.

y 7. A die-head having a body, chasers mounted therein, a cam-ring foroperating the chasers, a segment attached to the camring, asegment-extension projecting from the periphery of the die-head, acouplingstud carried by the segment, screws mounted in the cam-ring andengaging with said stud for adjusting the position of the segment withreference to the ring, a plate secured to the body, and a separatelyorganized threadcontrolling unit removably mounted in the said plate andhaving a plunger adapted to co-act with the said segment-extension andwith an abutment external to the die-head.

8. A die-head having a body, chasers mounted therein, a cam-ring foroperating thechasers, a spring for turning the camring to throw thechasers into their open positions, a segment carried by the cam-ring, asegment-extension, a coupling-stud carried by the segment, two screwsmounted in th VVand an interchangeable thread-controlling unit adaptedto be removably applied to the die-head and comprising a tubular body,a. spring-actuated plunger mounted therein and adapted katits lower endto control the chasers of the die-head, and having anadjustabletripping-finger adapted to 4co-act with an abutment external to thedie-head.

l0. A thread-controlling unit` for use with automatically openingdie-heads, the said -unit'consisting oli' a tubular body having itsupper end formed with a guide-slot, a spring-actuated plunger locatedv'in the said body and having its lower end adapted to coact with thecutting mechanism of the diehead' and having its upper endv slotted andthreaded, an adjusting-nut mounted upon the said body, and atripping-linger passing vthrough theslot of the plunger andbody,

held in place by the screw in the plunger', and resting upon the saidnut by which it is adjusted in position with respect to the said body. Y

1l. A die-head having a body, chasers mounted therein, a cam-ring foroperating the chasers, a spring for turning the ring to retire thechasers, a projection connected with the ring and extending laterally'from the die-head, a plate secured to the body and having an oisettingarm 'formed with a threaded opening, and a 'removable threadcontrollingunit mounted Vin the opening of thesaid arm and having a spring-actuatedplunger .carrying a tripping-finger for coaction with an abutmentexternal to the diehead, and formed at its lower end with a cone forco-action with the said projection, whereby the ring isturned in thedirection of opening the chasers, at a speed corresponding to the taperof the cone.

In testimony Vwhereof I havesigned this specification 1n the presence oftwo subscribing witnesses.`

ALBERT F. BREITENSTEIN.

Witnesses: f l

EDITH M. BUGKBEE, MARION E. THOMAS.

